I have a 97 3.8L camaro RS with manual transmission and about 150k miles on it, and I've been having acceleration problems. When i push the gas pedal more than just a little bit, the car starts to stumble and hesitate and it just won't accelerate normally. But if i do not depress the gas a lot, i can accelerate slowly and without any stumbling and hesitating all the way to highway speeds, and through all the gears. But if i give it any more gas than only about a quarter it starts stumbling; it will still accelerate but it is violent and not smooth and feels like it is hurting the engine. Air filter, fuel filter, cables and coils have been changed (though not the spark plugs, i think--which i hear from other people is kind of strange, but i don't know why exactly he didn't try changing the plugs): that was all due to my mechanic hitting and missing while trying to fix the problem. So if anyone would have any idea what exactly might fix the problem so that i can tell a mechanic to just fix THAT and to not guess at the problem, i would appreciate it very much.
thanks in advance
p.s. once i had poured in 91 octane gas (i usually use 87 because that is what the manual recommends) and it felt like the problem went away and i celebrated for about a day thinking that i had found the solution, but after a bit the problem came back, and i'm not sure whether it was because the next tank of 91 might have not been as good as the one that i thought fixed the problem, or perhaps there was no real connection here at all between the 'better gas' and the problem going away.

 

I had the same problem (my 97 RS is an automatic) and it turned out to be bad coil packs.

 

I'm having this same problem and I have done wires, plugs, coil pack, and O2 sensor. My uncle, my brother, and I have decided that injectors are the next step so hopefully this Sunday my baby will be running right.

 

Sounds like your timing is off. If the ignition timing is too retarted it will just bog down when you get on it. Does it act weird at other times or is it just when accelerating? A vacuum leak can cause that too but it would do it alot more often and act like it wants to die.